348 MR JOHN ALLAN BROUN ON THE HORIZONTAL FORCE 
97. The sixth week has two types, that of Makerstoun, Toronto, and Hobar- 
ton, consisting of marked minima about 5° 16°, and 74 4", with a secondary mini- 
mum about 6* 10"; and that of the Cape, Trevandrum, and Singapore, having 
only one well-marked minimum at 6° 10%, the time of the secondary minimum at 
the other stations. ; 
98. The best marked movement at all the stations during the six weeks is 
that after February 274 18"; the amounts of movement between 27 18° or 19", 
and 284 194, and 274 185 or 19, and the minima, are as follows— 
TABLE XXXI.—RanceEs or Movement (1:00=0 00014 X). 
SraTIoN. 274 18h to 284 19h, 274 18h to Min, 
Toronto, : ; 3 h 9:92 9-92 
Makerstoun, . , : 2 10-320 10:30 __ 
The Cape, . ; : : 6:62 6°62 
Trevandrum, . : : : 8:00 8°74 
Singapore, . ; ‘ : 5:06 5°68 
Hobaktonsey ities Lei aiiedee . 5-02 5°50 
The amount of the movement thus seems to diminish from the north towards 
the south; the diminution is, however, still small at Trevandrum, and it is 
nothing between Singapore and Hobarton. 
99. It is not easy to state the law of these differences from the consideration 
of a single period. It will be seen, Table XXVI., and by an examination of the 
projections, Plate XXVIL., that the amounts of movement are frequently equal at 
all the stations ; but we cannot state exactly how much of the differences aredu e 
to changes of magnetic dip, since there was no instrument well fitted to mark these 
changes at all the stations. An examination of the six weeks under discussion 
will show that the irregular variations of mean horizontal intensity are greatest 
and most common in the higher north latitudes, though some of the continuous 
movements are greatest near the equator. 
100. If we consider the whole range of the curves for the six weeks, Plate 
XXVIII., taking the difference between the highest point and the mean of the 
lowest preceding and following (by which we eliminate secular change, &c.), 
we shall have— 
Makerston. Toronto, Trevandrum. Singapore, The Cape, Hobarton. 
Ranges,. . . 14:27 11:91 12-12 9:02 12°60 9°89. 
101. And if we omit the point February 27? 18" before the great disturbance, 
we find— 

